Wales is located on a peninsula in central-west Great Britain. The entire area of Wales is about 20,779 km² (8,023 square miles). It is about 274 km (170 miles) long and 97 km (60 miles) wide. Wales borders by England to the east and by sea in the other three directions: the Bristol Channel to the south, St George's Channel to the west, and the Irish Sea to the north. Together, Wales has over 965 km (600 miles) of coastline. There are several islands off the Welsh mainland, the largest being Anglesey in the northwest.

The main population and industrial areas are in South Wales, including the capital, Cardiff, and the other two major cities, Swansea and Newport.

Much of Wales's diverse landscape is mountainous, particularly in the north and central regions. The mountains were shaped during the last ice age, the Devensian glaciation. The highest mountains in Wales are in Snowdonia, and include Snowdon, which, at 1085 m (3,560 feet) is the highest peak in England and Wales. The 14 Welsh mountains over 3000 feet high are known collectively as the Welsh 3000s.

The Brecon Beacons are in the south and are joined by the Cambrian Mountains in mid-Wales.

The Seven Wonders of Wales is a traditional list of seven geographic and cultural landmarks wonders in Wales: Snowdon (the highest mountain), the Gresford bells (the peal of bells in the medieval church of All Saints at Gresford), the Llangollen bridge (built in 1347 over the River Dee), St Winefride's Well (a pilgrimage site at Holywell in Flintshire) the Wrexham steeple (16th century tower of St. Giles Church in Wrexham), the Overton yew trees (ancient yew trees in the churchyard of St Mary's at Overton-on-Dee) and Pistyll Rhaeadr (Wales's tallest waterfall, at 240 feet or 75 m). The wonders are part of the traditional rhyme:

Pistyll Rhaeadr and Wrexham steeple,

Snowdon's mountain without its people,

Overton yew trees, St Winefride wells,

Llangollen bridge and Gresford bells.

National parks

Wales has three designated national parks.

Waterfalls

Wales has many waterfalls, including some of the most striking waterfalls of the United Kingdom. The tallest and most famous waterfall in Wales is Pistyll Rhaeadr at 75 m (240 feet). The name of the falls is Welsh for "spring of the waterfall" and is located near the village of Llanrhaeadr-ym-Mochnant in Powys. The waterfall is formed by the Afon Disgynfa river, passing over a Silurian cliff. At the end of the falls, the river continues and is known as the Afon Rhaeadr. The falls are counted as one of the Seven Wonders of Wales and is designated as the 1000th Site of Special Scientific Interest by the Countryside Council for Wales. for its importance to Welsh geomorphology. The 19th century English author George Borrow remarked of the waterfall, "I never saw water falling so gracefully, so much like thin, beautiful threads, as here."

Other waterfalls include Aber Falls (Welsh: Rhaeadr Fawr , "big waterfall") at Abergwyngregyn, as well as Hendryd Waterfall . Other waterfalls include the Rhaedr Cynfal falls in Ffestiniog (including Rhaeadr Y Cwm ) and Pistyll Blaen Y Cwm in the Marilyn Rhialgwm of the upper Tanat Valley .